Solid-state imaging apparatuses are required to have an improved S/N ratio and an increased dynamic range. In order to meet such requirements, an amplifier circuit and a detection circuit, which detects the signal level of each pixel signal, in each of columns of pixels arranged in a matrix are provided for each column in PTL 1. With this configuration, signal saturation in each column amplifier circuit is avoided, the gains of pixel signals are controlled such that small-amplitude ones do not cause saturation, and the gains are returned to the original values in a downstream circuit.
In PTL 2, a column amplifier circuit for each of columns generates a low-gain signal and a high-gain signal from each pixel signal from an imaging device. Signals obtained by returning high-gain signals to the same gain as the gain of low-gain signals and the low-gain signals are selectively combined to increase a dynamic range while maintaining an S/N ratio.
However, in the technique disclosed in PTL 1, a detection circuit for detecting a pixel signal is provided for each of columns of pixels, and the columns have different gains. A circuit for controlling the configuration is more complicated, and a solid-state imaging apparatus occupies a larger area. In addition, the pixels may have different S/N ratios.
In the technique disclosed in PTL 2, signals with different gains generated from each of a plurality of image signals are both subjected to AD conversion. This leads to an increase in the number of data transfer lines for AD-converted signals and a cost increase. If data transfer for one of the different gains and data transfer for the other gain are alternately and successively performed, transfer time doubles, and photographic speed decreases.